Folders vs collections?

[jsetsaas]

Hi,

Running Docker 10.10.7.

I am scanning a folder structure with private videos. 
It looks like all folders are imported, and most of them marked with a folder icon, when I look in the web GUI. However, some folders (apparently at random) show a collection icon (bookmark/mountain). 

The problem is that when the AppleTV app Infuse only shows folders, not collections.

The root problem is the marking of the folders. Why does this happen, and how can I reset it?
All folders have a combination of movies, nfo-files and posters. I am unable to understand why some of the folders are treated differently.

Any ideas?

[jsetsaas]

Update. I think I found the problem.
The folders which turns up as collections, had orphan images files in them (i.e. a .png or .jpg) which did not have a related movie file.

I would say that this is a bug in Jellyfin?